drivers/clk/qcom/clk-spmi-pmic-div.c - linux - Git at Google

 /* Copyright (c) 2017, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
  * only version 2 as published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */

 #include <linux/bitops.h>
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/log2.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
 #include <linux/types.h>

 #define REG_DIV_CTL1			0x43
 #define DIV_CTL1_DIV_FACTOR_MASK	GENMASK(2, 0)

 #define REG_EN_CTL			0x46
 #define REG_EN_MASK			BIT(7)

 struct clkdiv {
 	struct regmap		*regmap;
 	u16			base;
 	spinlock_t		lock;

 	struct clk_hw		hw;
 	unsigned int		cxo_period_ns;
 };

 static inline struct clkdiv *to_clkdiv(struct clk_hw *hw)
 {
 	return container_of(hw, struct clkdiv, hw);
 }

 static inline unsigned int div_factor_to_div(unsigned int div_factor)
 {
 	if (!div_factor)
 		div_factor = 1;

 	return 1 << (div_factor - 1);
 }

 static inline unsigned int div_to_div_factor(unsigned int div)
 {
 	return min(ilog2(div) + 1, 7);
 }

 static bool is_spmi_pmic_clkdiv_enabled(struct clkdiv *clkdiv)
 {
 	unsigned int val = 0;

 	regmap_read(clkdiv->regmap, clkdiv->base + REG_EN_CTL, &val);

 	return val & REG_EN_MASK;
 }

 static int
 __spmi_pmic_clkdiv_set_enable_state(struct clkdiv *clkdiv, bool enable,
 				    unsigned int div_factor)
 {
 	int ret;
 	unsigned int ns = clkdiv->cxo_period_ns;
 	unsigned int div = div_factor_to_div(div_factor);

 	ret = regmap_update_bits(clkdiv->regmap, clkdiv->base + REG_EN_CTL,
 				 REG_EN_MASK, enable ? REG_EN_MASK : 0);
 	if (ret)
 		return ret;

 	if (enable)
 		ndelay((2 + 3 * div) * ns);
 	else
 		ndelay(3 * div * ns);

 	return 0;
 }

 static int spmi_pmic_clkdiv_set_enable_state(struct clkdiv *clkdiv, bool enable)
 {
 	unsigned int div_factor;

 	regmap_read(clkdiv->regmap, clkdiv->base + REG_DIV_CTL1, &div_factor);
 	div_factor &= DIV_CTL1_DIV_FACTOR_MASK;

 	return __spmi_pmic_clkdiv_set_enable_state(clkdiv, enable, div_factor);
 }

 static int clk_spmi_pmic_div_enable(struct clk_hw *hw)
 {
 	struct clkdiv *clkdiv = to_clkdiv(hw);
 	unsigned long flags;
 	int ret;

 	spin_lock_irqsave(&clkdiv->lock, flags);
 	ret = spmi_pmic_clkdiv_set_enable_state(clkdiv, true);
 	spin_unlock_irqrestore(&clkdiv->lock, flags);

 	return ret;
 }

 static void clk_spmi_pmic_div_disable(struct clk_hw *hw)
 {
 	struct clkdiv *clkdiv = to_clkdiv(hw);
 	unsigned long flags;

 	spin_lock_irqsave(&clkdiv->lock, flags);
 	spmi_pmic_clkdiv_set_enable_state(clkdiv, false);
 	spin_unlock_irqrestore(&clkdiv->lock, flags);
 }

 static long clk_spmi_pmic_div_round_rate(struct clk_hw *hw, unsigned long rate,
 					 unsigned long *parent_rate)
 {
 	unsigned int div, div_factor;

 	div = DIV_ROUND_UP(*parent_rate, rate);
 	div_factor = div_to_div_factor(div);
 	div = div_factor_to_div(div_factor);

 	return *parent_rate / div;
 }

 static unsigned long
 clk_spmi_pmic_div_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
 {
 	struct clkdiv *clkdiv = to_clkdiv(hw);
 	unsigned int div_factor;

 	regmap_read(clkdiv->regmap, clkdiv->base + REG_DIV_CTL1, &div_factor);
 	div_factor &= DIV_CTL1_DIV_FACTOR_MASK;

 	return parent_rate / div_factor_to_div(div_factor);
 }

 static int clk_spmi_pmic_div_set_rate(struct clk_hw *hw, unsigned long rate,
 				      unsigned long parent_rate)
 {
 	struct clkdiv *clkdiv = to_clkdiv(hw);
 	unsigned int div_factor = div_to_div_factor(parent_rate / rate);
 	unsigned long flags;
 	bool enabled;
 	int ret;

 	spin_lock_irqsave(&clkdiv->lock, flags);
 	enabled = is_spmi_pmic_clkdiv_enabled(clkdiv);
 	if (enabled) {
 		ret = spmi_pmic_clkdiv_set_enable_state(clkdiv, false);
 		if (ret)
 			goto unlock;
 	}

 	ret = regmap_update_bits(clkdiv->regmap, clkdiv->base + REG_DIV_CTL1,
 				 DIV_CTL1_DIV_FACTOR_MASK, div_factor);
 	if (ret)
 		goto unlock;

 	if (enabled)
 		ret = __spmi_pmic_clkdiv_set_enable_state(clkdiv, true,
 							  div_factor);

 unlock:
 	spin_unlock_irqrestore(&clkdiv->lock, flags);

 	return ret;
 }

 static const struct clk_ops clk_spmi_pmic_div_ops = {
 	.enable = clk_spmi_pmic_div_enable,
 	.disable = clk_spmi_pmic_div_disable,
 	.set_rate = clk_spmi_pmic_div_set_rate,
 	.recalc_rate = clk_spmi_pmic_div_recalc_rate,
 	.round_rate = clk_spmi_pmic_div_round_rate,
 };

 struct spmi_pmic_div_clk_cc {
 	int		nclks;
 	struct clkdiv	clks[];
 };

 static struct clk_hw *
 spmi_pmic_div_clk_hw_get(struct of_phandle_args *clkspec, void *data)
 {
 	struct spmi_pmic_div_clk_cc *cc = data;
 	int idx = clkspec->args[0] - 1; /* Start at 1 instead of 0 */

 	if (idx < 0 || idx >= cc->nclks) {
 		pr_err("%s: index value %u is invalid; allowed range [1, %d]\n",
 		       __func__, clkspec->args[0], cc->nclks);
 		return ERR_PTR(-EINVAL);
 	}

 	return &cc->clks[idx].hw;
 }

 static int spmi_pmic_clkdiv_probe(struct platform_device *pdev)
 {
 	struct spmi_pmic_div_clk_cc *cc;
 	struct clk_init_data init = {};
 	struct clkdiv *clkdiv;
 	struct clk *cxo;
 	struct regmap *regmap;
 	struct device *dev = &pdev->dev;
 	struct device_node *of_node = dev->of_node;
 	const char *parent_name;
 	int nclks, i, ret, cxo_hz;
 	char name[20];
 	u32 start;

 	ret = of_property_read_u32(of_node, "reg", &start);
 	if (ret < 0) {
 		dev_err(dev, "reg property reading failed\n");
 		return ret;
 	}

 	regmap = dev_get_regmap(dev->parent, NULL);
 	if (!regmap) {
 		dev_err(dev, "Couldn't get parent's regmap\n");
 		return -EINVAL;
 	}

 	ret = of_property_read_u32(of_node, "qcom,num-clkdivs", &nclks);
 	if (ret < 0) {
 		dev_err(dev, "qcom,num-clkdivs property reading failed, ret=%d\n",
 			ret);
 		return ret;
 	}

 	if (!nclks)
 		return -EINVAL;

 	cc = devm_kzalloc(dev, struct_size(cc, clks, nclks), GFP_KERNEL);
 	if (!cc)
 		return -ENOMEM;
 	cc->nclks = nclks;

 	cxo = clk_get(dev, "xo");
 	if (IS_ERR(cxo)) {
 		ret = PTR_ERR(cxo);
 		if (ret != -EPROBE_DEFER)
 			dev_err(dev, "failed to get xo clock\n");
 		return ret;
 	}
 	cxo_hz = clk_get_rate(cxo);
 	clk_put(cxo);

 	parent_name = of_clk_get_parent_name(of_node, 0);
 	if (!parent_name) {
 		dev_err(dev, "missing parent clock\n");
 		return -ENODEV;
 	}

 	init.name = name;
 	init.parent_names = &parent_name;
 	init.num_parents = 1;
 	init.ops = &clk_spmi_pmic_div_ops;

 	for (i = 0, clkdiv = cc->clks; i < nclks; i++) {
 		snprintf(name, sizeof(name), "div_clk%d", i + 1);

 		spin_lock_init(&clkdiv[i].lock);
 		clkdiv[i].base = start + i * 0x100;
 		clkdiv[i].regmap = regmap;
 		clkdiv[i].cxo_period_ns = NSEC_PER_SEC / cxo_hz;
 		clkdiv[i].hw.init = &init;

 		ret = devm_clk_hw_register(dev, &clkdiv[i].hw);
 		if (ret)
 			return ret;
 	}

 	return devm_of_clk_add_hw_provider(dev, spmi_pmic_div_clk_hw_get, cc);
 }

 static const struct of_device_id spmi_pmic_clkdiv_match_table[] = {
 	{ .compatible = "qcom,spmi-clkdiv" },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, spmi_pmic_clkdiv_match_table);

 static struct platform_driver spmi_pmic_clkdiv_driver = {
 	.driver		= {
 		.name	= "qcom,spmi-pmic-clkdiv",
 		.of_match_table = spmi_pmic_clkdiv_match_table,
 	},
 	.probe		= spmi_pmic_clkdiv_probe,
 };
 module_platform_driver(spmi_pmic_clkdiv_driver);

 MODULE_DESCRIPTION("QCOM SPMI PMIC clkdiv driver");
 MODULE_LICENSE("GPL v2");
	/* Copyright (c) 2017, The Linux Foundation. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 and
	* only version 2 as published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*/

	#include <linux/bitops.h>
	#include <linux/clk.h>
	#include <linux/clk-provider.h>
	#include <linux/delay.h>
	#include <linux/err.h>
	#include <linux/log2.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/platform_device.h>
	#include <linux/regmap.h>
	#include <linux/slab.h>
	#include <linux/types.h>

	#define REG_DIV_CTL1 0x43
	#define DIV_CTL1_DIV_FACTOR_MASK GENMASK(2, 0)

	#define REG_EN_CTL 0x46
	#define REG_EN_MASK BIT(7)

	struct clkdiv {
	struct regmap *regmap;
	u16 base;
	spinlock_t lock;

	struct clk_hw hw;
	unsigned int cxo_period_ns;
	};

	static inline struct clkdiv to_clkdiv(struct clk_hw hw)
	{
	return container_of(hw, struct clkdiv, hw);
	}

	static inline unsigned int div_factor_to_div(unsigned int div_factor)
	{
	if (!div_factor)
	div_factor = 1;

	return 1 << (div_factor - 1);
	}

	static inline unsigned int div_to_div_factor(unsigned int div)
	{
	return min(ilog2(div) + 1, 7);
	}

	static bool is_spmi_pmic_clkdiv_enabled(struct clkdiv *clkdiv)
	{
	unsigned int val = 0;

	regmap_read(clkdiv->regmap, clkdiv->base + REG_EN_CTL, &val);

	return val & REG_EN_MASK;
	}

	static int
	__spmi_pmic_clkdiv_set_enable_state(struct clkdiv *clkdiv, bool enable,
	unsigned int div_factor)
	{
	int ret;
	unsigned int ns = clkdiv->cxo_period_ns;
	unsigned int div = div_factor_to_div(div_factor);

	ret = regmap_update_bits(clkdiv->regmap, clkdiv->base + REG_EN_CTL,
	REG_EN_MASK, enable ? REG_EN_MASK : 0);
	if (ret)
	return ret;

	if (enable)
	ndelay((2 + 3 * div) * ns);
	else
	ndelay(3 * div * ns);

	return 0;
	}

	static int spmi_pmic_clkdiv_set_enable_state(struct clkdiv *clkdiv, bool enable)
	{
	unsigned int div_factor;

	regmap_read(clkdiv->regmap, clkdiv->base + REG_DIV_CTL1, &div_factor);
	div_factor &= DIV_CTL1_DIV_FACTOR_MASK;

	return __spmi_pmic_clkdiv_set_enable_state(clkdiv, enable, div_factor);
	}

	static int clk_spmi_pmic_div_enable(struct clk_hw *hw)
	{
	struct clkdiv *clkdiv = to_clkdiv(hw);
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&clkdiv->lock, flags);
	ret = spmi_pmic_clkdiv_set_enable_state(clkdiv, true);
	spin_unlock_irqrestore(&clkdiv->lock, flags);

	return ret;
	}

	static void clk_spmi_pmic_div_disable(struct clk_hw *hw)
	{
	struct clkdiv *clkdiv = to_clkdiv(hw);
	unsigned long flags;

	spin_lock_irqsave(&clkdiv->lock, flags);
	spmi_pmic_clkdiv_set_enable_state(clkdiv, false);
	spin_unlock_irqrestore(&clkdiv->lock, flags);
	}

	static long clk_spmi_pmic_div_round_rate(struct clk_hw *hw, unsigned long rate,
	unsigned long *parent_rate)
	{
	unsigned int div, div_factor;

	div = DIV_ROUND_UP(*parent_rate, rate);
	div_factor = div_to_div_factor(div);
	div = div_factor_to_div(div_factor);

	return *parent_rate / div;
	}

	static unsigned long
	clk_spmi_pmic_div_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
	{
	struct clkdiv *clkdiv = to_clkdiv(hw);
	unsigned int div_factor;

	regmap_read(clkdiv->regmap, clkdiv->base + REG_DIV_CTL1, &div_factor);
	div_factor &= DIV_CTL1_DIV_FACTOR_MASK;

	return parent_rate / div_factor_to_div(div_factor);
	}

	static int clk_spmi_pmic_div_set_rate(struct clk_hw *hw, unsigned long rate,
	unsigned long parent_rate)
	{
	struct clkdiv *clkdiv = to_clkdiv(hw);
	unsigned int div_factor = div_to_div_factor(parent_rate / rate);
	unsigned long flags;
	bool enabled;
	int ret;

	spin_lock_irqsave(&clkdiv->lock, flags);
	enabled = is_spmi_pmic_clkdiv_enabled(clkdiv);
	if (enabled) {
	ret = spmi_pmic_clkdiv_set_enable_state(clkdiv, false);
	if (ret)
	goto unlock;
	}

	ret = regmap_update_bits(clkdiv->regmap, clkdiv->base + REG_DIV_CTL1,
	DIV_CTL1_DIV_FACTOR_MASK, div_factor);
	if (ret)
	goto unlock;

	if (enabled)
	ret = __spmi_pmic_clkdiv_set_enable_state(clkdiv, true,
	div_factor);

	unlock:
	spin_unlock_irqrestore(&clkdiv->lock, flags);

	return ret;
	}

	static const struct clk_ops clk_spmi_pmic_div_ops = {
	.enable = clk_spmi_pmic_div_enable,
	.disable = clk_spmi_pmic_div_disable,
	.set_rate = clk_spmi_pmic_div_set_rate,
	.recalc_rate = clk_spmi_pmic_div_recalc_rate,
	.round_rate = clk_spmi_pmic_div_round_rate,
	};

	struct spmi_pmic_div_clk_cc {
	int nclks;
	struct clkdiv clks[];
	};

	static struct clk_hw *
	spmi_pmic_div_clk_hw_get(struct of_phandle_args clkspec, void data)
	{
	struct spmi_pmic_div_clk_cc *cc = data;
	int idx = clkspec->args[0] - 1; /* Start at 1 instead of 0 */

	if (idx < 0 \|\| idx >= cc->nclks) {
	pr_err("%s: index value %u is invalid; allowed range [1, %d]\n",
	__func__, clkspec->args[0], cc->nclks);
	return ERR_PTR(-EINVAL);
	}

	return &cc->clks[idx].hw;
	}

	static int spmi_pmic_clkdiv_probe(struct platform_device *pdev)
	{
	struct spmi_pmic_div_clk_cc *cc;
	struct clk_init_data init = {};
	struct clkdiv *clkdiv;
	struct clk *cxo;
	struct regmap *regmap;
	struct device *dev = &pdev->dev;
	struct device_node *of_node = dev->of_node;
	const char *parent_name;
	int nclks, i, ret, cxo_hz;
	char name[20];
	u32 start;

	ret = of_property_read_u32(of_node, "reg", &start);
	if (ret < 0) {
	dev_err(dev, "reg property reading failed\n");
	return ret;
	}

	regmap = dev_get_regmap(dev->parent, NULL);
	if (!regmap) {
	dev_err(dev, "Couldn't get parent's regmap\n");
	return -EINVAL;
	}

	ret = of_property_read_u32(of_node, "qcom,num-clkdivs", &nclks);
	if (ret < 0) {
	dev_err(dev, "qcom,num-clkdivs property reading failed, ret=%d\n",
	ret);
	return ret;
	}

	if (!nclks)
	return -EINVAL;

	cc = devm_kzalloc(dev, struct_size(cc, clks, nclks), GFP_KERNEL);
	if (!cc)
	return -ENOMEM;
	cc->nclks = nclks;

	cxo = clk_get(dev, "xo");
	if (IS_ERR(cxo)) {
	ret = PTR_ERR(cxo);
	if (ret != -EPROBE_DEFER)
	dev_err(dev, "failed to get xo clock\n");
	return ret;
	}
	cxo_hz = clk_get_rate(cxo);
	clk_put(cxo);

	parent_name = of_clk_get_parent_name(of_node, 0);
	if (!parent_name) {
	dev_err(dev, "missing parent clock\n");
	return -ENODEV;
	}

	init.name = name;
	init.parent_names = &parent_name;
	init.num_parents = 1;
	init.ops = &clk_spmi_pmic_div_ops;

	for (i = 0, clkdiv = cc->clks; i < nclks; i++) {
	snprintf(name, sizeof(name), "div_clk%d", i + 1);

	spin_lock_init(&clkdiv[i].lock);
	clkdiv[i].base = start + i * 0x100;
	clkdiv[i].regmap = regmap;
	clkdiv[i].cxo_period_ns = NSEC_PER_SEC / cxo_hz;
	clkdiv[i].hw.init = &init;

	ret = devm_clk_hw_register(dev, &clkdiv[i].hw);
	if (ret)
	return ret;
	}

	return devm_of_clk_add_hw_provider(dev, spmi_pmic_div_clk_hw_get, cc);
	}

	static const struct of_device_id spmi_pmic_clkdiv_match_table[] = {
	{ .compatible = "qcom,spmi-clkdiv" },
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(of, spmi_pmic_clkdiv_match_table);

	static struct platform_driver spmi_pmic_clkdiv_driver = {
	.driver = {
	.name = "qcom,spmi-pmic-clkdiv",
	.of_match_table = spmi_pmic_clkdiv_match_table,
	},
	.probe = spmi_pmic_clkdiv_probe,
	};
	module_platform_driver(spmi_pmic_clkdiv_driver);

	MODULE_DESCRIPTION("QCOM SPMI PMIC clkdiv driver");
	MODULE_LICENSE("GPL v2");